What you find on this page:
Grant Boiler Error Codes
| Fault Code | Cause of Problem |
| No display | 12V transformer failure |
| PP1 | Inlet (return) water temperature sensor failure |
| PP1 | Inlet (return) water temperature sensor failure |
| PP2 | Discharge gas sensor failure |
| PP3 | Coil temperature sensor failure |
| PP4 | Return gas sensor failure |
| PP5 | Ambient temperature sensor failure |
| PP6 | Discharge gas overheat protection |
| PP7 | Winter anti-freeze protection in operation |
| EE1 | High pressure – circulating pump failure orcircuit air locked |
| EE2 | Low pressure |
| EE3 | Open circuit between PCB terminals 23-24 |
| EE4 | Supply L and N are reversed |
| EE8 | Communication failure |
| Flashing on and off | Defrosting |
| E01 | Internal control fault |
| sHr | HP flow sensor short / HP return sensor short |
| OPn | HP flow sensor open / HP return sensor open |
| SUP | Supply sensor short / Supply sensor open |
| OUTDR | Outdoor sensor short / Outdoor sensor open |
| C2849 | Fault C; Chassis Code Problem is controller area network wiring bus and modules. fault two; MFG – Manufacturer Specific Fault eight; Ignition System Or Misfire fault four; BBV Sensor Circuit Low Voltage fault nine; Kick-Down Switch Failed Short |
| U2453 | Fault U: Network Code Problem is climate control system, lighting, airbags, etc.. fault two; MFG – Manufacturer Specific fault four; Transmission fault five; TP Sensor Learn Not Complete fault three; Transmission Control Module Reprogrammable Memory |
